Aortic dissection

Question 1

What is the pathophysiology of an Aortic Dissection?

Answer 1

Tear in the tunic intima of the wall of the aorta

Question 2

What is a Type A - Aortic dissection?

Answer 2

ascending aorta, 2/3 of cases

Question 3

What are the risk factors for an Aortic dissection?

Answer 3

1. Hypertension - the most important risk factor
2. Trauma
3. bicuspid aortic valve
4. collagens: Marfan’s syndrome, Ehlers-Danlos syndrome
   Turner’s and Noonan’s syndrome
5. pregnancy
6. Syphilis

Question 4

What are the clinical signs of Aortic Dissection?

Answer 4

1. Pulse deficit
   - weak or absent carotid, brachial, or femoral pulse
   - variation (>20 mmHg) in systolic blood pressure between the arms

Question 5

What investigations are indicated for an Aortic Dissection? (3)

Answer 5

• ECG
  Most patients have none or non specific ECG changes
  ST elevations may be seen in inferior leads
• CXR
• Widened mediastinum
• CT angiography - chest, abdomen and pelvis
• Transoesophageal echocardiography for unstable patients who are too risky to take to CT scanner

Question 6

What is the management of a Type B - Aortic Dissection?

Answer 6

• Conservative management and bed rest
• Reduce blood pressure - IV labetalol to prevent progression

Question 7

What is the management of a Type A - Aortic Dissection?

Answer 7

• surgical management

Question 8

What are the symptoms of an Aortic Dissection?

Answer 8

1. Chest/Back pain
   * Typically severe and ‘sharp’, ‘tearing’ in nature
   * Pain is typically maximal at onset
   * Classicallychest pain is more common in type A dissection and upper back pain is more common in type B dissection.

Question 9

What is a Type B - Aortic dissection?

Answer 9

type B - descending aorta, distal to left subclavian origin, 1/3 of cases